Method of making dihalo acrylonitriles



Patented Sept. 1 943 .mz'rnon or name DIHALO acarmmrarms '10 G. Lichty, Stow. Ohio, asaignor to wingloot Corporation Delaware Akron. Ohio, a 'ot No mm, Application June 3, 1941. 'Serial No. 396.427

2 Claims- (Cl. 280-}84} This invention relates to a method of treating certain halogenated nitriles with a basic reagent, to obtain products with a reduced proportion of halogen therein. and, more particularly, to a method of treating halogenated propionltriles with a tertiary amine.

In accordance with the terms of the invention, it has been Iound, that propionitriles containing two or three halogen atoms may be treated with a tertiary amine to remove halogen in the form of hydrogen halide. the hydrogen halide usually forming a hydrohalide of the tertiary amine. The compounds thus obtained will be nitriles containing less hydrogen and less halogen than the starting materials. The method is especially useful in the preparation of unsaturated nitriles for use in polymerization's leading to the production of industrial materials. The illustrate, dichloro isobutyro nitrile may be reacted with quinoline to yield alpha methyl beta chloro acrylonitrile. The reaction is. of course, useful for the preparation of other similar compounds, depetiglling on the starting materials which are reac The reaction is applicable to the treatment of the" class of alpha beta dlhalo propionitril'es which contain additionally, in the alpha position, one oi the group consisting of alkyl and halogen radicals. That is to say, tertiary amines maybe reacted with alpha alkyl alpha beta dihalo propionitriles and with alpha, alpha, beta,

.trihalo propionitriles. In each instance. the

isoquinoline, quinaldine, lepidine, alpha, beta and gamma phenyl pyrldines' and. in general, tertiary amines which have a boiling point above approximately 200 C. -However, lower boiling tertiaryamines may be used if a solution 01! the nitrile and the amine be passed through a heated tube and therein subjected to a high temperature for a sutflcient period of time to eifect the reaction..

In this procedure lower boiling tertiary amines may be used, such as pyridine, picolines, lutidines, collidines, trimethylamine, triethylamine and tripropylamine. Whichever procedure is employed, thetemperature should be raised to about 200 C. to complete the separation.

To illustrate the method, the following ex-- amples are. given, although it will be understood that the invention is not limited thereto.

out. Among such may be mentioned quinoline,

Example 1 A mixture of 84.5 grams of dichloro isobutyro nitrile and grams of quinoline is distilledr After the distillation has been completed, the quinoline and quinoline hydrochloride is removed to obtain 34.4 grams cl 9. product boiling lie-- tween and 158 C. The'product is a mixture of the cis and trans forms of alpha methyl beta chloro acrylonitrile. The reaction is believed to proceed as follows:

CH Cl-E-Cl-CN Example 2 Two mols (317 grams) of trichloro propionitrile and 2 grams of hydroquinone were placed in a 500 cc. 3-necked flask provided with a distillation condenser, a thermometer and a dropping funnel. The nitrilewas heated on an oil bath to C. and a temperatrue of 1-50-163 C. was maintained for a period of hour during the addition of 258 grams ofquinoline and the heating was thencontinued to a final temperature of 210 0., during which a' total 01. 208 grams of product distilled out. Application of reduced pressure gave an additional yield of 7 grams. Redi'stillation of the product resulted in the recovery of 132 grams of dichloro acrylonitrlle boiling at 55-65 C./60 mm. and 68.3 grams of a product boiling at 64-79 C./60 mm., the higher boiling fraction being chiefly trichloro propionitrile. A yield of 69.3% 01' the trichloro propionitrile consumed was obtained. The reaction proceeds as follows:

The conditions given above for the conduct I oi nitrile being treated and the temperature may a be adjusted to secure the greatest conversion of the halogenated nitrile, a temperature ranging from 125 to 250 C. being effective in most instances. The product should be removed from the sphere of reaction as fast as formed to avoid interaction with the base and this is easily accomplished since the unsaturated nitrile has a boiling point lower than the base or the nitrile starting material. Thus, the product will be distilled on as formed and the reaction is completed when no further product comes over. In addition to the halo nitriles mentioned, other starting materials which can be subjected to the process are alpha ethyl alpha beta dichloro propionitrile, alpha methylalpha beta dibromo propionitrile, alpha ethyl alpha beta dibromo propionitrile, and similar saturated halo propionitriles containing at least two halogen atoms in the molecule.

While there have been described above the preterred embodiments of the invention, it will be apparent to those skilled in the art that various modifications and changes may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. The method of reacting a trihalopropionltrile with a tertiary amine having a boiling pointabove about 200 C. to remove hydrogen halide and produce a dihalo acrylonitrile which comprises distilling the dihalo acrylonitrile from the sphere of the reaction substantially as soon as it is formed.

2. The methodoi' reacting a tertiary amine having a boiling point above about 200 c. with trichloropropionitrile to remove hydrogen chloride and produce dichloro acrylonitrile which comprises heating the reaction to a final temperature of about 200 C. to remove the dichloro acrylonitrile from the sphere of the reaction sub- 20 stantially as soon as it is formed.

JOY G. LICHTY. 

